<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    * {
      padding: 0;
      margin: 0;
    }
    .app {
      height: 100vh;
      width: 100vw;
    }
    .head {
      background-color: skyblue;
      height: 100px;
      width: 100%;
    }
    /* .container {
      padding: 0 300px 0 200px;
      height: calc(100% - 200px);
    } */
    .container > div {
      float: left;
    }

    /* 左侧栏 */
    .left {
      width: 200px;
      height: 100vh;
      margin-left: -100%;
      background-color: red;
    }

    /* 右侧栏 */
    .right {
      width: 200px;
      height: 100vh;
      margin-left: -200px;
      background-color: blue;
    }

    /* 中间栏 */
    .middle {
      width: 100%;
      height: 100vh;
      background-color: pink;
    }
    .main {
      padding: 0 200px;
    }

    .footer {
      height: 100px;
      width: 100%;
      background-color: skyblue;
    }
  </style>
  <body>
    <div class="app">
      <!-- <div class="head">head</div> -->
      <div class="middle">
        <div class="main">中间自适应内容</div>
      </div>
      <div class="left">左侧固定宽度</div>
      <div class="right">右侧固定宽度</div>

      <!-- <div class="footer">footer</div> -->
    </div>
  </body>
</html>
